Machine and method for making a sub-unit of a smoking article

ABSTRACT

A machine for making sub-units of smoking articles comprises a conveyor, a feed unit, cutting means and at least one rotary applicator. The conveyor is configured to feed a succession of tubular segments of the tobacco industry. The feed unit is configured to feed and convey at least one continuous web. The cutting means are configured to separate a succession of closing elements from a front end of the continuous web. The rotary applicator is operatively associated with the conveyor and is configured to pick up the succession of closing elements and to apply them, preferably by gluing, to an application end of a respective tubular segment, in such a way as to form closing walls to at least partly close the application ends.

TECHNICAL FIELD

This invention addresses the technical field of the production of articles of the tobacco industry.

This invention relates in particular to a machine and a method for making a sub-unit of a smoking article, which may be for example a smoking article of the type configured to generate aerosol by heating, preferably without burning, or an electronic cigarette.

In this context, in order to be able to ensure the quality of the finished product, it is very important to guarantee that the active material—that is, the material that generates the aerosol—is correctly contained and retained both during the production process and during use of the article.

BACKGROUND ART

Prior art production methods involve making a smoking article composed of a rod-shaped body (for example a filter or a heating element) and a tube made of wrapping material which is then filled with the aerosol-generating element.

However, that solution is not well suited to guaranteeing the integrity of the article, in particular because it does not allow guaranteed correct retaining of the aerosol-generating element, that is to say, the active portion of the smoking article, inside the tubular wrapping material when a smoker inhales.

That means that during use of the smoking article, the aerosol generating element could come out of its sub-unit and find its way into the adjacent ones, thus negatively affecting the operation of the product.

Indeed, the effect of the smoker puffing at the smoking article could have the undesirable result of causing the aerosol generating element or any of the other materials making up the smoking article to come out of the sub-unit.

AIM OF THE INVENTION

In this context, the technical purpose which forms the basis of this invention is to propose a machine and a method for making a sub-unit of a smoking article which overcomes at least some of the above-mentioned disadvantages of the prior art.

In particular, the aim of this invention is to provide a machine and a method for making a sub-unit of a smoking article capable of optimising the production process by simultaneously improving the quality and the stability of the finished product which can be made.

The technical purpose specified and the aims indicated are substantially achieved by a machine and a method for making a sub-unit of a smoking article, comprising the technical features set out in one or more of the appended claims.

Accordingly this invention provides a machine for making sub-units of smoking articles which comprises a conveyor, a feed unit, cutting means and at least one rotary applicator.

The conveyor is configured to feed a succession of tubular segments of the tobacco industry.

The feed unit is configured to feed and convey a continuous web.

The cutting means are configured to separate a succession of closing elements from a front end of the continuous web.

The at least one rotary applicator is operatively associated with the conveyor and is configured to pick up the succession of closing elements and to apply them, preferably by gluing, to an application end of a respective tubular segment, in such a way as to form closing walls to at least partly close the application ends.

Preferably, the cutting means are configured to separate from the continuous web closing elements having a size such that they partly cover the application end.

Alternatively, the cutting means are configured to separate from the continuous web closing elements having a size such that they completely cover the application end.

Advantageously, the machine described herein allows application of the closing elements on the tubular segments, in such a way as to make sub-units having suitable closing walls in at least one of their ends

That device prevents material from accidentally going through the closed end of the segment itself.

This invention also relates to a method for making a sub-unit of a smoking article which comprises the steps of:

-   -   preparing a tubular segment of the tobacco industry, being         internally provided with a through duct terminating with end         openings of the tubular segment;     -   applying a closing element on at least one application end of         the tubular segment by means of a rotary applicator, in such a         way as to form a closing wall to at least partly close that         application end.

Advantageously, the method proposed herein supplies a rapid and efficient procedure for applying a closing wall to a tubular segment, in such a way as to make a sub-unit capable of guaranteeing correct retaining of the filling material of the smoking article into which it will be inserted.

This invention also relates to a smoking article which comprises an aerosol-generating segment, a filtering segment and at least one spacer tube interposed between the two segments.

In particular, the spacer tube has one end at least partly closed by a closing element applied to an application end of it to at least partly close that application end.

In particular, the closing element is interposed between the spacer tube and one of either the aerosol-generating segment or the filtering segment.

Preferably, the spacer tube directly abuts against the aerosol-generating segment and/or against the filtering segment.

Preferably, the smoking article comprises an additional segment, in particular a tubular cooling segment.

In particular, the additional segment is interposed between the spacer tube and the aerosol-generating segment or between the spacer tube and the filtering segment.

Preferably, the spacer tube abuts directly against the additional segment in such a way that the closing element is directly interposed between the spacer tube and the additional segment.

Preferably, the closing element is made of material that is porous and/or has a plurality of holes or perforations suitable for increasing the air and/or gas permeability of the closing wall.

Preferably, the closing element is made of metallic material, even more preferably the closing element is made of aluminium.

Preferably the closing element is made of fire-resistant material.

Advantageously, the particular structural configuration of the smoking article guarantees, by the presence of the closing wall interposed between adjacent segments, that the filling material is retained correctly, preventing it from migrating inside the smoking article and preferably also from coming out of it.

Also an object of this invention is a method for making a smoking article, comprising the following steps:

-   -   preparing a filtering segment     -   preparing an aerosol-generating segment;     -   preparing a spacer tube having one end at least partly closed         with a closing element applied in an application end of it, to         at least partly close that application end,     -   aligning along a predominant line of extension the filtering         segment, the aerosol-generating segment and the spacer tube in         such a way that the closing element is interposed between the         spacer tube and one of either the aerosol-generating segment or         the filtering segment.

Preferably, the method further comprises the steps of:

-   -   preparing an additional segment, in particular a cooling segment         which is preferably tubular.     -   interposing the additional segment between the spacer tube and         one of either the aerosol-generating segment or the filtering         segment, directly abutting the spacer tube against the         additional segment in such a way that the closing element is         directly interposed between the two.

Advantageously, the method described herein allows a smoking article to be made which has a closing wall to prevent the passage of the filling material of the article itself from one portion of it to another.

The dependent claims, which are incorporated herein by reference, correspond to different embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of this invention are more apparent in the indicative, non-limiting description below, with reference to a preferred, but non-exclusive embodiment of a machine and a method for making a sub-unit of a smoking article, as illustrated in the accompanying drawings in which:

FIG. 1 schematically illustrates the main components of a machine according to this invention;

FIGS. 2 to 6 show in detail different possible embodiments of several of the components of the machine of FIG. 1;

FIGS. 7 and 8 show sub-units made by the machine and according to the method disclosed;

FIG. 9 is a cross-section of a smoking article.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

In the accompanying figures the reference number 10 generically indicates a machine for making sub-units 20 of smoking articles, hereinafter in this description indicated simply as the machine 10.

The machine 10 comprises a conveyor 11, a feed unit 12, cutting means 13 and at least one rotary applicator 14.

The conveyor 11 is configured to feed a succession of tubular segments 21 of the tobacco industry.

For example, the conveyor 11 may be made in the form of a conveyor drum, a conveyor belt or other conveying devices having appropriate seats suitable for retaining the tubular segments.

In particular, each tubular segment 21 has an axis of predominant extension, around which the tubular segment 21 extends and preferably defining an axial axis of symmetry of the tubular segment 21 itself.

Moreover, each tubular segment 21 is internally provided with a through duct, which terminates with respective openings at opposite ends of the tubular segment 21. At each of the end openings, each tubular segment 21 has an annular front surface delimiting the above-mentioned through duct. Those front surfaces lie in respective planes which are parallel to each other and perpendicular to the above-mentioned axis of predominant extension.

In other words, the interior of the tubular segment 21 defines a duct, which also acts as a containment chamber for containing a filling material of the tobacco industry and which terminates in the open ends of the tubular segment 21 itself.

By way of a non-limiting example, the through duct may therefore contain a filling material such as an aerosol-generating material, tobacco pellets, tobacco which is loose or in another form, flavouring material (for example micro-capsules containing a flavouring liquid) or a filtering material (activated carbon, silica gel or others known in the reference sector) or even a material with cooling effect (such as PLA pellets).

The feed unit 12 is configured to feed a continuous web “N”, preferably by unwinding a reel housed on a suitable support, and to convey it, for example by means of guide elements such as one or more idle or motor-driven rollers.

The cutting means 13 are operatively associated with the feed means 12 to engage the continuous web “N” along its conveying path and are configured to separate a succession of closing elements 22 from a front end of that continuous web “N”.

In particular, the cutting means 13 are configured to make a cut across the full width of the continuous web “N”.

Preferably, the cutting means 13 comprise a pair of cutting drums which operate in conjunction with each other to separate a succession of closing elements from a front end of the continuous web “N”.

In particular, the pair of cutting drums comprises a first drum 13 a whose surface is provided with a succession of cutting blades configured to engage the continuous web “N” to separate the succession of closing elements therefrom.

The pair of cutting drums also comprises a second drum 13 b configured to convey the continuous web “N” until it engages the cutting blades of the first drum.

The second drum 13 b is also configured to radially space the individual closing elements after they have been separated from the continuous web “N”.

The applicator 14 is in particular a rotary applicator operatively associated with the conveyor 11 and is configured to pick up the succession of closing elements, in particular from the cutting means 13, and to apply each closing element 22 to an application end of a respective tubular segment 21.

In particular, the applicator 14 comprises an applicator wheel which has a plurality of seats disposed radially and set equal distances apart along its circumference.

Those seats are moved, by the rotation of the applicator wheel along a circular path in which they sequentially engage the cutting means 13, receiving from them and retaining a succession of closing elements 22, and then the conveyor 11, for application of the closing elements on respective application ends of the tubular segments 21.

According to the invention, the applicator 14 is configured and/or disposed to release each closing element 22 on a front wall of a respective closing element 22. In particular, the applicator 14 is configured and/or disposed to move each closing element 22 along a trajectory having at least one component parallel to the axis of predominant extension of the respective tubular segment 21 on which the closing element 22 must be applied.

According to one embodiment, schematically shown in FIG. 2, the applicator wheel has an axis of rotation “R” perpendicular to the axis of predominant extension of the tubular segments as they are conveyed by the conveyor 11. That configuration and positioning of the applicator wheel 14 defines a circular conveying trajectory which is at a tangent to the trajectory followed by the front surface of the respective tubular segment 21 on which the closing element 22 must be applied.

Alternatively, as is schematically shown in FIGS. 3 to 6, the applicator wheel has an axis of rotation “R” which is inclined relative to an axis of predominant extension of the tubular segments 21 when these are being carried by the conveyor, being preferably inclined at an angle between 30° and 60° and still more preferably, at an angle of 45°. That configuration and positioning of the applicator wheel 14 defines a circular conveying trajectory which is in any case at a tangent to the trajectory followed by the front surface of the respective tubular segment 21 on which the closing element 22 must be applied.

Therefore, according to the invention the applicator 14 causes a gradual movement of the closing elements 22 towards the respective tubular segments 21 in such a way as to release the closing elements 22 so that they rest on the front surface of the respective tubular segment 21.

Therefore, by applying the closing element 22 a closing wall is created which at least partly closes the application end on which that closing element 22 has been placed.

In particular, the closing wall provides a barrier which prevents any filling material of the smoking article 30 into which the sub-unit 20 will be placed from passing through the application end of the tubular segment 21.

At the same time, the closing wall must be such as to allow the passage of air and/or gas and/or aerosol through the end of the sub-unit 20, in particular in the direction of a smoker during use of the smoking article 30 into which the sub-unit 20 has been inserted.

According to a first possible embodiment, the closing element 22 has an overall size such that it completely covers the application end.

Alternatively, the closing element 22 has an overall size such that it only partly covers the application end.

If the closing wall completely covers the application end of the tubular segment 21, in order to guarantee the correct inflow of air and/or gases and/or aerosol through the sub-unit 20, the closing element 22 is made of material which is porous and/or has a plurality of holes or perforations suitable for increasing the air or gas permeability of the closing wall.

In other words, if the closing wall is such that it completely closes off access to the duct defined inside the tubular segment 21, the closing element 22 is made in such a way as to in any case allow the passage of air and/or gas and/or aerosol either because it is made of porous material and/or because it has suitable openings.

For that purpose, the machine 10 comprises perforating means, operating in particular on the continuous web “N” to make holes or perforations configured to allow air or gas to pass through them.

Preferably, the perforating means comprise at least one laser.

In contrast, if the closing wall only partly covers the application end of the tubular segment 21, the correct inflow of air and/or gas and/or aerosol through the sub-unit 20 is guaranteed by those portions of the application end which remain uncovered, therefore the closing element 22 may even be made of material which is impermeable to air.

It is also possible for the closing element 22 to in any case be made of material which is porous or which has a plurality of holes or perforations suitable for increasing the air and/or gas permeability of the closing wall, even if the closing element 22 only partly closes the application end.

In particular, the closing element 22 may be made of metallic material, for example of aluminium.

Preferably, the closing element 22 is made of fire-resistant material.

In general, the machine 10 further comprises folding means, disposed downstream of the at least one applicator 14, which are configured to fold against an external surface (that is to say, cylindrical) of the tubular segment 21 end or peripheral portions of the respective closing element 22 protruding beyond an external profile of the application end (that is to say protruding radially outwards from the above-mentioned annular front wall of the tubular segment 21).

The presence of the folding means, whose structure will be described in more detail below, therefore allows improved adhesion of the closing element 22 to the tubular segment 21, by increasing their surface area of contact with each other.

Moreover, the folding means allow improvement of the structural integrity of the sub-unit 20 by removing any protruding portions of the closing element 22 which could strike further portions of semi-finished products or operating devices during any further operating steps which the sub-unit 20 must be subjected to.

Preferably, coupling of the closing element 22 to the respective tubular segment 21 is performed by gluing.

For that purpose, the machine 10 comprises a gumming device configured to apply an adhesive substance on the application end of the tubular segment 21 and/or on the closing element 22.

In other words, the gumming device is operatively associated either with the conveyor 11 or with the feed unit 12 in order to apply respectively on the application end or on the continuous web “N” an adhesive substance which will subsequently allow the closing element 22 and the tubular segment 21 to be constrained to each other at the application end.

Preferably, the gumming device is configured to apply the adhesive substance only on the portion of the closing element 22 or of the tubular segment 21 intended to come into contact respectively with the application end or with the closing element 22.

In other words, the adhesive layer is applied according to a pattern which traces the profile where the closing element 22 and the application end of the tubular segment 21 are superposed, in contrast leaving free the part of the closing element 22 which is directly facing the duct defined by the tubular segment 21.

The machine 10 further comprises detecting means configured to check the position of the closing element 22 relative to the application end.

By way of example and without limiting the scope of the invention, the detecting means may comprise optical sensors such as video cameras or acoustic sensors such as ultrasonic sensors.

According to one particular embodiment, the machine 10 may comprise a pair of rotary applicators 14 configured to apply respective successions of closing elements 22 on respective application ends of each tubular segment 21.

According to one particular aspect of this invention, the conveyor 11 is configured to feed a succession of double-length tubular segments 21 of the tobacco industry.

The expression double-length tubular segment 21 denotes a tubular segment 21 whose length is such that the tubular segment can be divided into two distinct parts of equal length suitable for making two respective single-length tubular segments 21 of a smoking article 30.

In other words, the double-length tubular segment 21 is suitable to be divided into two distinct parts along its centre line “M” to make two distinct tubular segments 21 each usable for making a smoking article 30.

According to that embodiment, the machine 10 comprises a pair of rotary applicators 14, which are configured to apply respective successions of closing elements 22 on respective opposite application ends of each double-length tubular segment 21.

Moreover, the machine 10 comprises separating means, for example rotary blades, which are disposed upstream or downstream of the pair of applicators 14.

The separating means are configured to cut the double-length tubular segment 21 along a midplane, in particular to make a succession of pairs of tubular segments 21, which are preferably identical in terms of structure and size.

In this context, the folding means are movable, in particular along a line perpendicular to the application end and are configured to engage portions of the closing elements 22 that protrude beyond an edge of the respective application ends.

Operatively, the movable folding means are disposed downstream of the pair of applicators 14 and/or of the separating means.

According to a further possible embodiment, the machine comprises the separating means, but they are disposed upstream of the pair of applicators 14 and the machine 10 further comprises retracting means 15, which are disposed downstream of the separating means.

The retracting means 15 are configured to axially space the pair of tubular segments 21 resulting from the cutting, by the separating means, of the double-length tubular segments 21.

In particular, the retracting means 15 are configured to separate the tubular segments 21 in such a way that each tubular segment 21 has a first end that is directed towards the other tubular segment 21 and that is spaced from it and a second end that is opposite to the first end.

According to this embodiment, the machine 10 comprises a pair of rotary applicators 14 which in this context are configured to apply respective successions of closing elements 22 on respective application ends of the pair of tubular segments 21, wherein in particular the application ends are defined by the first ends of the tubular segments 21.

The machine 10 therefore comprises axially fixed folding means, that is to say, not movable, which are disposed along a feed path of the pair of tubular segments 21, in such a way as to be placed between the tubular segments 21 which define the pair of tubular segments 21. Preferably, the folding means are mounted on the conveyor in such a way as to be facing the tubular segments 21 as they are conveyed.

In this context, the tubular segments 21 are associated with movable elements configured to axially shift the tubular segments 21 while they are being conveyed, so that the application end engages the folding means.

The fixed folding means are configured to fold against an external surface of the tubular segment 21 portions of the respective closing element 22 protruding beyond the edge of the application end.

The machine 10 also comprises movement means configured to axially move the pair of tubular segments towards each other in such a way as to engage the folding means.

According to a first aspect of that embodiment, the retracting means 15 comprise a retracting drum and the rotary applicators 14 are associated with it in order to apply the closing elements 22 to tubular segments 21 disposed on the retracting drum.

In particular, the retracting drum comprises a plurality of movable elements, which define respective retaining seats for the tubular segments 21, and are longitudinally translatable relative to the axis of predominant extension of the tubular segments 21 which they convey in such a way as to space them out.

Alternatively, according to a further aspect of that embodiment, the retracting means 15 comprise a retracting drum and a pair of conveyor drums disposed side by side and spaced from each other.

The pair of conveyor drums is disposed downstream of the retracting drum to receive from it respective successions of tubular segments.

In this context, each rotary applicator 14 is associated with a respective conveyor drum to apply the closing elements 22 on tubular segments 21 disposed on the respective conveyor drum.

According to one particular embodiment, if the tubular segments 21 conveyed are of double length, the feed unit 12 is configured to feed a double-width continuous web “N”.

In this context, the machine 10 further comprises dividing means configured to cut the continuous web “N” along its line of predominant extension, in such a way as to operatively separate it into two single-width continuous webs “N” which will then be fed to respective cutting means 13.

Advantageously, this invention achieves the preset aims and overcomes the disadvantages of the prior art by providing the user with a machine for making sub-units 20 of smoking articles 30 which allows making a succession of sub-units 20 which are each provided with a closing wall adapted to hold the filling material within the smoking article 30, in particular after the finished product has been assembled.

This invention also relates to a method for making a sub-unit 20 of a smoking article 30.

The method comprises preparing a tubular segment 21 of the tobacco industry, in particular a tubular segment 21 which is internally provided with a through duct terminating with end openings of the tubular segment 21.

The method then comprises applying a closing element 22 on at least one application end of the tubular segment 21 by means of a rotary applicator 14, thereby forming a closing wall, which at least partly closes the application end.

The step of applying the closing element 22 is carried out by applying the closing element 22 resting on the front wall of the respective tubular segment 21, in particular on the annular front wall of the respective tubular segment 21.

In particular, the applying step is carried out by moving the closing element 22 along a trajectory having at least one component parallel to the axial axis of symmetry of the respective tubular segment 21.

That trajectory is at a tangent to the trajectory followed by the application end of the respective tubular segment 21 and is preferably circular.

In particular, the closing element 22 is made starting from a continuous web “N”, which is fed and made available for processing, for example by unwinding it from a suitable reel.

The continuous web “N” is then cut to make a succession of closing elements whose size and shape allow them to be applied on respective application ends.

The method described herein comprises in particular cutting the continuous web “N” across the full width of that continuous web “N”.

In this way, the whole of the continuous web “N” is substantially divided into a succession of closing elements 22 without the presence or creation of any waste or offcut portions or in any case without any portions of the continuous web “N” being left over which must be disposed of because they are not suitable for making a closing element 22 or part of one.

After they have been separated from the continuous web “N”, for example as already indicated by using the cutting means 13, the closing elements 22 are picked up by the at least one rotary applicator 14 which will take them near to the tubular segments 21 and apply them at the respective application ends.

Preferably, the method comprises applying an adhesive substance on the application end of each tubular segment 21 and/or on the respective closing element 22 according to a specific, predetermined pattern.

Similarly to what has already been indicated relative to the operation of the gumming device of the machine 10, the predetermined pattern is preferably a pattern which as accurately as possible traces the shape of the contact surface between the closing element 22 and the application end, in such a way that only the parts of them which must effectively be placed in contact with each other have a layer of adhesive on them.

In order to guarantee the correct inflow of air through the closing wall, the method further comprises increasing the air and/or gas permeability of the closing wall, preferably by making a plurality of holes or perforations in the continuous web “N” before cutting it.

That step intended to improve the permeability of the closing wall is carried out in particular if the material used to make the closing element 22 is impermeable to gases, but may also be carried out if the closing element 22 is made using a material which is naturally porous.

According to one particular aspect of this invention, the step of applying the closing element 22 is carried out by applying a pair of closing elements 22 simultaneously on each application end of the tubular segments 21. According to a different aspect of this invention, the step of preparing a tubular segment 21 is carried out by preparing a double-length tubular segment 21 and the method further comprises carrying out a step of cutting the double-length tubular segment 21 along its midplane, in such a way as to obtain two tubular segments 21 of the tobacco industry.

The cutting step may be carried out upstream or downstream of application of the closing element 22.

The cutting step is carried out in such a way that the tubular segments 21 have first ends abutted against each other at the midplane of the double-length tubular segment 21 from which they were created and second ends opposite the first ends.

According to a first possible embodiment, the closing element 22 is applied by applying a pair of closing elements 22 simultaneously on opposite application ends of the tubular segments 21 of the pair of tubular segments 21, that is to say, those made by cutting a double-length tubular segment 21 into two distinct parts.

In particular, the application ends are defined by the second ends of the tubular segments 21.

Alternatively, if cutting of the double-length tubular segment 21 precedes application of the closing elements 22, the method may comprise axially spacing the pair of tubular segments 21 in such a way that their first ends are separate and facing each other.

In this situation, the step of applying the closing element 22 is carried out by applying a pair of closing elements 22 on facing application ends of the tubular segments 21 of the pair of tubular segments 21, wherein the application ends are defined by the first ends.

Advantageously, this invention achieves the preset aims and overcomes the disadvantages of the prior art by providing the user with a method for making a sub-unit 20 of a smoking article 30 which can guarantee the structural integrity of the finished product in which the sub-unit 20 thus made will be included.

This invention also relates to a smoking article 30, in particular a smoking article 30 which comprises sub-units 20 made using the machine and/or the method described above.

In particular, the smoking article 30 comprises an aerosol-generating segment 31, a filtering segment 32 and a spacer tube.

The aerosol-generating segment 31 is preferably a tubular segment 21 into which an aerosol-generating material of the tobacco industry has been inserted.

The filtering segment 32 is preferably a tubular segment 21 made of material suitable for making a filter of the tobacco industry, or a tubular segment 21 filled with a filtering material of the tobacco industry.

The spacer tube is preferably an empty tubular segment 21 which is interposed between the aerosol-generating segment 31 and the filtering segment 32 in such a way as to separate them.

The spacer tube has one end at least partly closed by a closing element 22 applied in an application end of it to at least partly close that application end.

In particular, the closing element 22 is interposed between the spacer tube and at least one of either the aerosol-generating segment 31 or the filtering segment 32.

Preferably, the spacer tube is directly abutted against the aerosol-generating segment 31 or against the filtering segment 32.

According to one particular embodiment, shown in FIG. 9, the smoking article 30 comprises an additional segment 32 interposed between the spacer tube and the aerosol-generating segment 31 or interposed between the spacer tube and the filtering segment 32.

Therefore, the spacer tube is directly abutting the additional segment 32 in such a way that the closing element 22 is directly interposed between the spacer tube and the additional segment 32.

The additional segment 32 is preferably a tubular segment 21 filled with a cooling material of the tobacco industry.

Advantageously, the smoking article 30 described herein overcomes the disadvantages of the prior art, since the presence of the closing wall guarantees correct retaining of the aerosol-generating element inside the smoking article 30 preventing its unwanted escape or its inhalation by a smoker.

This invention also relates to a method for making a smoking article 30 which comprises preparing a filtering segment 32, an aerosol-generating segment 31 and a spacer tube, all three preferably being made as indicated above.

In particular, the spacer tube is made using a tubular segment 21 which has one end at least partly closed by a closing element 22 applied on an application end of it to at least partly close the application end.

The method therefore comprises aligning along a predominant line of extension the filtering segment 32, the aerosol-generating segment 31 and the spacer tube in such a way that the closing element 22 is interposed between the spacer tube and the aerosol-generating segment or between the spacer tube and the filtering segment 32.

The method may also advantageously comprise a step of preparing an additional segment 32, in particular a cooling segment which is preferably tubular.

During alignment of the various elements intended to form the smoking article 30, the additional segment 32 is interposed between the spacer tube and the aerosol-generating segment or between the spacer tube and the filtering segment 32.

In particular, the additional segment 32 is applied by abutting it directly against the spacer tube, in such a way that the closing element 22 is directly interposed between the spacer tube and the additional segment 32.

Advantageously, the method described herein allows a smoking article 30 to be made which is particularly strong and of high quality, in which correct retaining (and consequent operation) of the filling material present inside it is guaranteed. 

1. A machine for making sub-units of smoking articles, comprising: a conveyor configured to feed a succession of tubular segments of the tobacco industry; a feed unit for feeding a continuous web; cutting means configured to separate a succession of closing elements from a front end of the continuous web; at least one rotary applicator, operatively associated with the conveyor and configured to pick up the succession of closing elements and to apply each closing element, preferably by gluing, to an application end of a respective tubular segment in such a way as to form closing walls to at least partly close the application ends.
 2. The machine according to claim 1, wherein the at least one applicator is configured and/or disposed to release each closing element on a front wall of the respective closing element, in particular an annular front wall of the respective closing element.
 3. The machine according to claim 2, wherein the at least one applicator is configured and/or disposed to cause a gradual movement of the closing elements towards the respective tubular segments in such a way as to release the closing elements so that they rest on the front surface of the respective tubular segment.
 4. The machine according to claim 1, wherein the at least one applicator is configured and/or disposed to move each closing element along a trajectory having at least one component parallel to an axial axis of symmetry of the respective tubular segment on which the closing element must be applied.
 5. The machine according to claim 4, wherein said trajectory is at a tangent to the trajectory followed by the application end of the respective tubular segment on which the closing element must be applied and is preferably circular.
 6. The machine according to claim 1, comprising folding means, disposed downstream of the applicator drum, which are configured to fold against an external cylindrical surface of the tubular segment end portions of the respective closing element, in particular end portions radially protruding beyond an external profile of the application end.
 7. The machine according to claim 1, comprising perforating means operating on the continuous web to make holes or perforations configured to allow air or gas to pass through them, the perforating means preferably comprising at least one laser.
 8. The machine according to claim 1, wherein the at least one rotary applicator comprises an applicator wheel.
 9. The machine according to claim 8, wherein the applicator wheel has an axis of rotation which is transversal, in particular perpendicular, to an axis of predominant extension of the tubular segments when these are being carried by the conveyor.
 10. The machine according to claim 8, wherein the applicator wheel has an axis of rotation that is inclined to an axis of predominant extension of the tubular segments when these are being carried by the conveyor, the axis of rotation being preferably inclined at an angle between 30° and 60° and, still more preferably, at an angle of 45°.
 11. The machine according to claim 1, comprising a gumming device configured to apply an adhesive substance on the application end of the tubular segment and/or on the closing element.
 12. The machine according to claim 1, comprising a pair of rotary applicators configured to apply respective successions of closing elements on respective application ends of each tubular segment.
 13. The machine according to claim 1, wherein the conveyor is configured to feed a succession of double-length tubular segments of the tobacco industry and the machine comprises a pair of rotary applicators configured to apply respective successions of closing elements on respective application ends of each double-length tubular segment.
 14. The machine according to claim 13, comprising separating means, disposed upstream or downstream of the pair of applicators and configured to cut the double-length tubular segment along a midplane to make a succession of pairs of tubular segments.
 15. The machine according to claim 14, wherein the separating means are disposed upstream of the pair of applicators, and also comprising retracting means disposed downstream of the separating means and configured to axially space the tubular segments of the pair of tubular segments in such a way that each tubular segment has a first end that is directed towards the other tubular segment and that is spaced from that tubular segment and a second end that is opposite to the first end.
 16. The machine according to claim 15, wherein the pair of rotary applicators is configured to apply respective successions of closing elements on respective application ends of the pair of tubular segments, the application ends being defined by the first ends.
 17. The machine according to claim 15, wherein the retracting means comprise a retracting drum and the rotary applicators are associated with the retracting drum to apply the closing elements on tubular segments disposed on the respective conveyor drum.
 18. The machine according to claim 15, wherein the retracting means comprise a retracting drum and a pair of conveyor drums disposed side by side and spaced from each other, the pair of conveyor drums being disposed downstream of the retracting drum to receive from the retracting drum respective successions of tubular segments, and wherein each rotary applicator is associated with a respective conveyor drum to apply the closing elements on tubular segments disposed on the retracting drum.
 19. The machine according to claim 15, wherein the folding means are axially fixed, disposed along a feed path of the pair of tubular segments in such a way as to be placed between the tubular segments of the pair of tubular segments and configured to fold against an external surface of the tubular segment portions of the respective closing element protruding beyond an edge of the application end, and also comprising movement means configured to axially move the pair of tubular segments towards each other in such a way as to engage the folding means.
 20. The machine according to claim 1, wherein the cutting means are configured to cut the continuous web across the full width of the continuous web.
 21. The machine according to claim 1, comprising detecting means configured to check the position of the closing element relative to the application end.
 22. A method for making a sub-unit of a smoking article, comprising the steps of: preparing a tubular segment of the tobacco industry, the tubular segment being internally provided with a through duct terminating with end openings of the tubular segment; applying a closing element on at least one application end of the tubular segment by means of a rotary applicator in such a way as to form a closing wall to at least partly close that application end.
 23. The method according to claim 22, wherein the applying step is carried out by applying the closing element resting on a front wall of the respective tubular segment, in particular an annular front wall of the respective tubular segment.
 24. The method according to claim 22, wherein the applying step is carried out by moving the closing element along a trajectory having at least one component parallel to an axial axis of symmetry of the respective tubular segment.
 25. The machine according to claim 24, wherein said trajectory is at a tangent to the trajectory followed by the application end of the respective tubular segment and is preferably circular.
 26. The method according to claim 22, wherein the step of applying the closing element is preceded by the steps of: feeding at least one continuous web of material suitable for making the closing element; cutting the continuous web to make a closing element suitable for being applied on the respective application end; picking up the closing element by means of the rotary applicator.
 27. The method according to claim 26, wherein the step of cutting the continuous web to make the closing element is accomplished by cutting the continuous web across the full width of the continuous web.
 28. The method according to claim 22, comprising a step of applying an adhesive substance on the application end of the tubular segment and/or on the closing element according to a specific, predetermined pattern.
 29. The method according to claim 22, comprising a step of increasing the air and/or gas permeability of the closing wall, preferably by making a plurality of holes or perforations in the continuous web before cutting it.
 30. The method according to claim 22, wherein the step of applying the closing element is carried out by applying a pair of closing elements simultaneously on each application end of the tubular segments.
 31. The method according to claim 22, wherein the step of preparing a tubular segment is carried out by preparing a double length tubular segment and wherein the method further comprises, before or after the step of applying the closing element, a step of cutting the double-length tubular segment along a midplane to obtain two tubular segments of the tobacco industry having first ends abutted against each other at the midplane and second ends opposite the first ends.
 32. The method according to claim 31, wherein the step of applying the closing element is carried out by applying a pair of closing elements simultaneously on opposite application ends of the tubular segments of the pair of tubular segments, the application ends being defined by the second ends.
 33. The method according to claim 31, comprising a step of axially spacing the pair of tubular segments and wherein the step of applying the closing element is carried out by applying a pair of closing elements on facing application ends of the tubular segments of the pair of tubular segments, the application ends being defined by the first ends. 